Tunica Adventitia Research Articles

Anaesthetic management of a parturient with Takayasu’s arteritis coming for emergency caesarean section

Takayasu’s arteritis (TA) also known as pulseless disease is a rare disease that involves aorta and its main branches. It can cause inflammatory reaction of tunica media and adventitia of the arteries involved causing stenosis, occlusion or aneurysm., Anaesthesia for caesarean section in a parturient with Takayasu’s arteritis is complicated by associated hypertension, end organ dysfunction, stenosis of major blood vessels and overall vasculopathy.The optimal anaesthetic management in a parturient with Takayasu’s arteritis is controversial, but avoidance of regional anaesthesia has been recommended by some authors because of the risk of hypotension and the subsequent need for vasopressors., We herein report the use of general anaesthesia in a term parturient with Takayasu’s arteritis coming for emergency Lower segment caesarean section (LSCS).

Revealing Layer‐Specific Ultrastructure and Nanomechanics of Fibrillar Collagen in Human Aorta via Atomic Force Microscopy Testing: Implications on Tissue Mechanics at Macroscopic Scale

Soft biological tissues are natural biomaterials with structures that have evolved to perform physiological functions, for example, conferring elasticity while preserving the mechanical integrity of arteries. Furthermore, the mechanical properties of the tissue extracellular matrix (ECM) significantly affect cell behavior and organ function. ECM mechanical properties are strongly affected by collagen ultrastructure, and perturbations in collagen networks can cause tissue mechanical failure. It is thus crucial to understand the ultrastructural mechanical properties of soft tissues. Herein, the ultrastructural and nanomechanical properties of arterial tissues are reported. Specifically, maps of aorta tissue stiffness in its three constitutive layers, namely tunica intima, media, and adventitia, are reported. Atomic force microscopy (AFM) with large and ultrasharp tips is used to explore tissue stiffness at two scales. Quasistatic tensile tests are further conducted to understand a potential correspondence between small‐scale mechanical properties obtained via AFM indentation and macroscopic behavior of the tissue at low and large strains. Furthermore, gradients in stiffness across the various layers as well as deformation rate effects are investigated. It is envisioned that the established methodology serves as a tool to investigate the effect of ECM remodeling associated with vascular diseases such as aneurysms and arterial stiffening linked to hypertension.

Light Reflectance Characterization of Waste Glass Coating for Tiles

Glass wastes that come from recycling plants do not often find a proper use, thus, they are discarded. In order to find future uses for these wastes, this paper explores the characterization of waste glasses (WGs) as a raw material through the assessment of their light reflectance if they were used for external coatings in building materials. To this aim, in this research, several clay-tile specimens were fabricated and coated with three different compositions of waste glass. For these specimens, three variables were analyzed to serve for this WG-based coating characterization: thickness of WG coating, temperature, and holding time of burning. The resulting WG-coated tiles were assessed in terms of the light spectral reflectance and whiteness index, with the help of a fiber optic spectrometer. Results show that the composition of WG had a very significant influence on the light spectral reflectance and the degree of whiteness, with holding time and WG thickness being the most influential depending on the WG type. The temperature of burning was also shown to be critical for the densification process. Finally, an interpretation of these results based on the WG chemical composition coatings obtained by XRF is discussed in this paper.

Photocrosslinking of Adventitial Collagen in the Porcine Abdominal Aorta: A Preliminary Approach to a Strategy for Prevention of Aneurysmal Rupture

This study was aimed at generating data for designing a potential method to prevent the rupture of the abdominal aortic aneurysm (AAA). We found that the mechanical strength and stiffness of blood vessel walls was enhanced by the crosslinking of adventitial collagen through a photochemical process promoted by ultraviolet-A (UV-A) radiation. The experiments were carried out on samples isolated from 25 normal porcine aortas. The adventitial layer was separated from the other layers and exposed to UV radiation of 365-nm wavelength, in the presence of a riboflavin compound as the photosensitizer. Mechanical testing of 30 specimens, prior to and after exposure, indicated an increase in both strength (ultimate stress) and stiffness (Young’s modulus) of the adventitial specimens following irradiation. The crosslinking process also led to an enhanced resistance to experimental collagenolysis, as determined on six specimens. At this phase of conceptual design, we suggest that by applying this method to an aneurysmal dilated wall region, the stabilization of tunica adventitia may delay or prevent the rupture of the aneurysm and, with further investigation and refinement, can become a therapeutic strategy for arresting the progression of AAA.

Long-term effect of recycled aggregate on microstructure, mechanical properties, and CO2 sequestration of rendering mortars

This study aimed to investigate the effect of replacing 30% natural fine aggregate with recycled aggregate (RA) produced from construction and demolition waste (C&DW) on the long-term properties of Portland cement rendering mortars. For this purpose, mortars were produced using natural aggregate (REF), crushed recycled aggregate (CRA), and sieved crushed recycled aggregate (CSRA). The mortars were applied as external coating, and properties such as their adhesion, compressive and flexural strengths were evaluated, as well as their microstructure using X-ray diffraction (XRD), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR) after 1,059 days of exposure. Visual surface analysis was performed on the external coating to identify the cracking. After 1,059 days of exposure, the CRA and CSRA mortars showed adhesion strength statistically equal to REF and significantly higher than the minimum values ​​established by standard for internal and external coatings. Regarding 1,059-day compressive and flexural strengths, respective increments of 39 and 42% were observed for the CRA composition compared to REF. No cracks were observed in any of the mortars after 1,059 days. Furthermore, the CO2 assessment indicated net CO2 emission reductions of 59 and 38% for CSRA and CRA, respectively, compared to REF. Overall, the incorporation of RA resulted in mortars with superior long-term mechanical properties and a significantly lower net CO2 emission than the mortar with natural aggregate.

Pathological Study on the Expression of Vasohibins in Peripheral Artery Disease.

Vasohibin-2 (VASH2) is a gene that promotes local angiogenesis. The tubulin carboxypeptidase activity of vasohibin causes detyrosination of alpha-tubulin and may play an important role in the regulation of various phenomena. Pathological and therapeutic angiogenesis are involved in atherosclerotic lesions. This study aimed to investigate whether the expression of VASH2 is associated with peripheral artery disease (PAD) in relation to angiogenesis, tubulin detyrosination, and severity of atherosclerotic lesions. An analysis of femoral and tibial arteries obtained from 86 patients with PAD or abdominal aortic aneurysm (AAA) was performed. The expressions of cluster of differentiation 31, VASH1, VASH2, and detyrosinated alpha-tubulin (DT-tubulin) were examined by immunohistochemistry, and their association with PAD was analyzed. The counts of VASH2 in the tunica media and adventitia in the tibial artery were significantly higher than those in the femoral artery in the PAD (P = 0.005 and P = 0.008, respectively) and AAA (P = 0.002 and P < 0.001, respectively) groups. In the tunica media and adventitia, VASH2 was significantly correlated with DT-tubulin. There was no significant difference in the expression of VASH2 and DT-tubulin in medial smooth muscle cells (McNemar test, P > 0.999). This study revealed the possible involvements of VASH2 in atherosclerosis by two methods-one maybe related to the progression of atherosclerosis by inducing angiogenesis and the second may be related to the decrease in arterial elasticity by increasing DT-tubulin in medial smooth muscle cells.

Identification of novel pulmonary vein nodes as generators of ectopic arrhythmic foci for atrial fibrillation: an immunohistochemical proof.

The atrial muscle sleeve (AMS) of the pulmonary vein is the most common source of the arrhythmogenic triggers in atrial fibrillation (AF). Anatomical substrate generating these ectopic currents is still elusive. The present study was designed to study the AMS of pulmonary veins with an emphasis on the structural basis which might govern AF initiation and perpetuation. The study was conducted on a longitudinal tissue section of pulmonary vein, taken from 15 human cadaveric nondiseased hearts. Tissue was studied histologically using H&E and Gömöri trichrome stain. The pacemaker channels were identified by immunohistochemistry using monoclonal HCN4 and HCN1 antibodies. The AMS was identified in each pulmonary vein, located between the tunica adventitia and tunica media. A node-like arrangement of myocytes was seen within the AMS in 30% of veins. It had a compact zone limited by a fibrous capsule and contained much smaller, paler and interconnected myocytes. Outside the capsule, there was a zone of dispersed, singly placed myocytes separating the compact zone from the working myocytes of the AMS. HCN4 and HCN1 antibodies were expressed on the cell membrane of nodal myocytes, while the working myocytes demonstrated none to minimal staining. Pulmonary veins nodes are similar to the specialized cardiac conductive tissue in the histological arrangement of compact and transitional zones, cellular characteristics and the presence of pacemaker channels. They might be the anatomical basis of ectopic arrhythmogenic foci. To our knowledge, these nodes are being described for the first time in human.

Optimal Preparation and Characterization of Self-Curing Concrete Containing Internal Superabsorbent Polymer and External Waterborne Epoxy Coating

Optimal Preparation and Characterization of Self-Curing Concrete Containing Internal Superabsorbent Polymer and External Waterborne Epoxy Coating

Effect of Sr, Mg and Fe substitution on the physico-chemical and biological properties of Si[sbnd]Ca[sbnd]P multilayer scaffolds

In this work, a new combination of ceramic materials is proposed for bone tissue engineering applications. Multilayer scaffolds consisting of a core composed mainly of calcium pyrophosphate and external coatings of silica and calcium doped with Fe3+, Sr2+ and Mg2+ were prepared. To study the influence of the arrangement of dopant ions in the external coatings, two different scaffolds were developed: scaffolds 3J consisting of a single external coating with 9mol% of Fe3+, Sr2+ and Mg2+ ions; and scaffolds 3S comprising three external coatings, each containing 3mol% of Fe3+, Sr2+ and Mg2+ ions. Scaffolds were physico-chemically characterized and evaluated for in vitro bioactivity and cellular response in the presence of MG-63 cells. The results showed that the core scaffold displayed no in vitro bioactivity or good cellular response, but served as a support for the external coatings given its mechanical resistance. The cell viability of scaffolds 3J and 3S increased more than 100% in relation to the core, and also improved cell proliferation and adhesion resulting in a dense layer of cells that covered the scaffolds’ entire surface. The arrangement of ions in the external coatings did not influence the cellular response, but determined the bioactivity rate.

Evaluation of Freeze-Thaw Durability of Silica Fume Concrete with Spraying Inorganic Coating Using Ultrasonic Testing

To study the antifreezing durability of internal coating silicon fume concrete with different external coatings, fast freeze-thaw (FT) cycle testing was performed for three types of external coatings applied to the internal coatings of silicon fume concrete. Using ultrasonic testing and compressive strength tests, we analysed the relationships between the ultrasonic pulse velocity and the mechanical and physical properties of concrete under freeze-thaw action. The results show that the compressive strength and pulse velocity of the studied concrete changed little before the first 100 FT cycles but varied significantly after being subjected to 100 FT cycles and diminished linearly with increasing FT cycles. The dynamic elastic parameters of the concrete were inferred using pulse velocity calculations, and the dependence on FT cycles was very similar to that of ultrasonic pulse velocity. The concrete strength was strongly and positively correlated with ultrasonic pulse velocity. The linear regression model of between ultrasonic pulse velocity, kinetic coefficient, and compressive strength of concrete was also established. The damage incurred to the external coating material (XT-HPA + XT-SS and XT-HPS) was small, and the good performance of the concrete with the added inorganic coating after freeze-thaw cycles indicates good frost resistance.

Research and development of processes of vacuum ion-plasma parts surface treatment

The application of electron-ion-plasma technologies for increasing the service life of machine parts, tools and technological equipment has been investigated. The technology of vacuum ion-plasma surface treatment is proposed for the deposition of coatings, which makes it possible to create internal, external and combined coatings. The manufacturability of coating methods is largely determined by the level of the developed equipment. The entire technological process of deposition of wear-resistant coatings on parts of friction units is carried out in one cycle on a BRV600F vacuum unit, which is equipped with all the necessary technical means. A method has been developed for the technology of obtaining a superhard carbon-metal coating with desired properties, namely, improving the quality of diamond-like films by changing their structure and composition, while the lower layer should have high adhesion to the substrate material, the middle layer should have high hardness and increased wear resistance, and the upper layer should have good thermal conductivity and heat resistance with low coefficient of friction.

A Bio-Based Render for Insulating Agglomerated Cork Panels

Natural and bio-based thermal insulation materials play an important role in the lifecycle impact of buildings due to their influence on the amount of energy used in indoor temperature control and the environmental impact of building debris. Among bio-based materials, cork is widespread in the Mediterranean region and is one of the bio-based materials that is most frequently used as thermal insulation for buildings. A particular problem is the protection of the cork-agglomerated panels from external stress and adverse weather conditions; in fact, cork granulates are soft and, consequently, cork panels could be damaged by being hit or by excessive sun radiation. In this study, an innovative external coat for cork-agglomerated panels made of a blending composite of beeswax and rosin (colophony) is proposed. The performance of this composite, using different amounts of elements, was analysed to discover which mix led to the best performance. The mix of 50% beeswax and 50% rosin exhibited the best performance out of all the mixes. This blend demonstrated the best elongation and the lowest fracture density, characteristics that determine the durability of the coating. A performance comparison was carried out between cork panel samples coated with lime render and beeswax–rosin coating. The coating of beeswax and resin highlighted a detachment value about 3.5 times higher than the lime plaster applied on the side of the cork.

Topographic and anatomical characteristics of the bladder neck in early fetuses

Aim. To determine macro-and microscopic anatomical characteristics and the dynamics in topographic and anatomical interactions of the bladder neck with adjacent organs and structures at the beginning of the fetal period. Material and methods. The study was carried out on 70 fetal specimens. The age of subjects included in the study was determined according to the tables of B.M. Patten, B.P. Khvatova, Yu.N. Shapovalov based on measurements of the parietal-calcaneal length (PCL), taking into account the Instructions for determining the perinatal period, live birth, and stillbirth criteria, approved by Order of the Ministry of Health of Ukraine No. 179 dated March 29, 2006. To achieve this goal, the following methods of anatomical research were used: anthropometry - to determine the age of the studied subjects; injection of arterial vessels with subsequent dissection under the control of a microscope – to study the peculiarities of the blood supply to the vesicoureteral segment; radiography - to determine the skeletotopy of the vesicoureteral segment; macro-microscopy – to explore the anatomical relationships of the components of the vesicoureteral segment, their structure, shape, position; histological – to study the structure of the wall of the vesicoureteral segment; morphometry – to determine the morphometric parameters of the vesicoureteral segment; 3-D reconstruction method – to study the spatial structure of the vesicoureteral segment; statistical – to analyze and establish the reliability of differences in organometric parameters.Results. Skeletopically, the projection of the vesicoureteral junction of early fetuses is located at the level of the upper third of the pubic symphysis. At the beginning of the perinatal period in female fetuses, the bladder neck (6.9 ± 2.6 mm) is longer than in male fetuses (6.4 ± 2.4 mm). Based on the analysis and generalization of the research results, it is substantiated that at the beginning of the fetal period, the internal urethral sphincter can be formed: a) by two loops of the outer longitudinal layer; b) the ring of the circular layer and the front bundles of the outer longitudinal layer; c) anterior bundles of the outer longitudinal layer and transverse bundles of the inner longitudinal layer within the trigone of urinary bladder; d) a ring of the circular layer, thickened in the anterolateral sections.Conclusions. Considering the topographic and anatomical characteristics of the angio- and myoarchitectonics of the vesicoureteral segment, we believe that its role as a physiological sphincter of the lower urinary tract is provided by the interaction of the vascular and muscle components. The vascular component of the sphincter apparatus of the vesicoureteral segment is provided by veins located in three layers: 1) cavernous-like veins of the submucosa; 2) veins of the muscular membrane; 3) veins of tunica adventitia. The second anatomical component of the sphincter function of the vesicoureteral segment is the muscular one, represented by the internal urethral sphincter.

Mixtures of Scutellaria baicalensis and Glycyrrhiza L. Extracts as Antibacterial and Antiviral Agents in Active Coatings

The aim of this study was to develop active packaging materials covered in active coatings (offering antibacterial and antiviral properties) that contain selected plant extracts. In addition, the synergistic effect of the active substances in these extracts was also analysed. The results of the study demonstrated that Scutellaria baicalensis and Glycyrrhiza L. extracts (two of six analysed plant extracts) were the most active agents against selected Gram-positive and Gram-negative bacterial strains. Additionally, the synergistic effect of S. baicalensis and Glycyrrhiza L. extracts was noted, meaning that the effect of these two plant extract mixtures on Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas syringae growth was higher than the activity of individual pure extracts. Mixtures of the extracts were introduced into the coating carrier. A polyethylene (PE) foil was then coated with active layers containing mixtures of S. baicalensis and Glycyrrhiza L. extracts as antimicrobial agents. The results of this research showed that all of the active coatings had a bacteriolytic effect on B. subtilis and a bacteriostatic effect on S. aureus cells. The coatings were found to be inactive against E. coli and P. syringae cells. This means that the coatings could be used as internal coatings to preserve food products against Gram-positive bacteria that may be responsible for food spoilage. The results of this study also demonstrated that the coatings were highly active against phage phi 6 phage particles, used as SARS-CoV-2 surrogate. This means that the coatings could be used as external coatings to limit the spread of SARS-CoV-2 and pathogenic Gram-positive bacteria via human hands.

Seasonal variations in histomorphology and histochemistry of vesicular gland of buffalo bull

The present study was conducted to study the seasonal changes in the histomorphology and histochemistry of the vesicular gland of buffalo bull. The vesicular gland of buffalo bull was collected from the abattoir immediately after sacrifice during winter and summer season. The tissue sample were fixed in 10% neutral buffered formalin (NBF) and were processed for paraffin blocks preparation by acetone-benzene schedule and paraffin sections of 3-5 μm were obtained on glass slides with rotary microtome. The paraffin sections were stained with various stains to study the histomorphological and histochemical parameters. The results showed that the vesicular glands were compound tubulo-alveolar type of gland in buffalo and were composed of four layers, i.e. lamina epithelialis, propria submucosa, tunica muscularis and tunica adventitia. In winter, the lumen of acini became wider than summer. The secretory material was observed during winter but could not be seen in summer season both in glandular acini and ducts. The connective tissue of stroma was less in winter and increased in summer which may be the reason for reduced lumen of glandular acini in summer. The tunica muscularis layer was thicker in winter than in summer season. The micrometrical data revealed that the average epithelial height and acinar diameter significantly decreased from winter to summer. The activity of neutral mucopolysaccharides, basic proteins, lipids and phospholipids were more in winter than summer season. The acid mucopolysaccharides were more in summer than winter. The results indicate that the vesicular gland of buffalo bull was more functionally active during winter season as compared to summer season.

Abstract 10478: Comprehensive Mechanical Modelling of Thoracic Endovascular Aortic Repair in Type A Aortic Dissection

Background: Thoracic endovascular aortic repair (TEVAR) in selected proximal (Stanford type A) aortic dissection (TAAD) cases has been reported, however, the limitation and criteria for TEVAR applied in TAAD remain controversial. Virtual stent-graft (SG) deployment simulation based on the finite element method is an emerging tool that allows TEVAR to be reproduced for detailed analysis of biomechanical interaction between native vessel wall and SG device. Methods: A TAAD patient underwent an unsuccessful TEVAR followed by salvage open surgical repair. Pre-TEVAR CT angiogram was used to establish the 3D geometry of the dissected aorta for later analysis. Perioperative DSA was used to measure the aortic root motion and determine SG position in the simulation model. Specimen of the harvested aortic tissue was used for histological analysis and tensile test to define isotropic hyperelastic properties of the aortic wall. Results: Aortic root motion was decomposed into a component normal to the sinotubular junction (STJ) and a component parallel to the STJ. The largest motion was 4.14 mm in normal direction and 3.5 mm in parallel direction. The continuous motion was used to define the displacement boundary condition at the aortic root in a finite element model. The histology revealed preserved both elastic fibres and collagen at the proximal landing zone. A small area of inflammatory infiltration was noted at the tunica externa which may related to the dissected lamella. Tensile testing showed that the aortic wall ruptured at the stress of 250-1250 kPa while the lamella ruptured at 80-160 kPa. Simulation precisely reproduced the SG configuration after TEVAR procedure. Maximum principal stress at 301 kPa was found on the lamella during simulation, which is significantly higher than stress tolerance of the lamella. Conclusion: Microstructure of the lamella and aortic wall components determine the capacity in resisting SG induced focal stress. During the deployment, the proximal end of SG landed directly onto the lamella where the maximum stress exceeded the tolerance of the lamella thus causing rupture and allowing the SG to penetrate into the false lumen.

A histological and immunohistochemical study on the parabronchial epithelium of the domestic fowl's (Gallus gallus domesticus) lung with special reference to its scanning and transmission electron microscopic characteristics.

The current study was designed to give complete histo-and immunohistochemical features of the parabronchial epithelium of domestic fowl's (Gallus gallus domesticus) lung with special reference to Scanning electron microscope (SEM) and mean transmission electron microscope (TEM) features. The lung exhibited variable-sized atrial openings encircled by exchange tissue zones. The parabronchial atrial chambers appeared as ovoid and polygonal-shaped that separated by the well-developed interatrial septum. The deep atrial lumens had blood vessels pierced by openings that represent the infundibula. The parabronchial blood capillaries meshwork was branched and exhibited ovoid-shaped air capillaries with numerous extravasated blood vessels. By TEM, there were several air capillaries and groups of squamous and endothelial respiratory cells and the squamous cells had oval nucleus with evenly distributed chromatin. The endothelial respiratory cells had few microvilli on their free surfaces. The parabronchial tubes opened into a group of widened atria that had smooth muscle bundles at the interatrial septa. The atrial chambers led to narrow infundibula. Moreover, the lining epithelium of parabronchi, atria, infundibula, and air capillaries was formed by simple squamous epithelium. Air capillary walls were lined by two types of respiratory cells (Types-I and II). Collagen fibers were concentrated within the tunica externa layers of the parabronchial blood vessels as well as, they were observed in CT interparabronchial septa. Immunohistochemically, the elastin immunoreactivity was detected around the parabronchial blood vessels, at the base of each parabronchial atria, and in the area encircling the alveolar-capillary walls. Our work concluded that there are a relation between the fowl's lifestyle and the surrounding environmental conditions.

GP.3 Examining Aneurysmal Healing After Flow Diversion Treatment Using Endovascular Optical Coherence Tomography

Background: The mechanism of aneurysmal healing after flow-diversion treatment of cerebral aneurysms remains unknown. The purpose of this research to is to utilize a novel technology called endovascular optical coherence tomography (OCT) to characterise and improve our understanding of aneurysmal healing after flow-diversion using a rabbit aneurysm model. Methods: Saccular aneurysms were created in 10 New Zealand white rabbits. The aneurysms were treated with a flow-diverting stent 28 days after creation. OCT and histopathologic examinations included: luminal thrombosis, endothelial loss, inflammation, fibrin, smooth muscle cell loss, disruption of the internal and external elastic lamina, and tunica adventitia changes Results: OCT revealed endothelialization across the stent, appearing to originate from the parent vessel, along with small amounts of thrombus on the stent-struts. Minimal thrombus was visualized within the aneurysm sac. Histologic examination revealed that OCT can accurately define endothelialization across the sent, and define patent segments across the neck. Conclusions: Aneurysmal healing appears to originate at the parent vessel/stent interface, and use the stent as a scaffold to grow across the neck of the aneurysm. Minimal thrombus was visualized within the aneurysm sac, with ongoing flow observed in the setting of incomplete neck endothelialization. This technology has great potential for assessing aneurysmal healing in real-time.

Bridging Coronary Physiology into Clinical Application of Acute Coronary Syndrome

Normal arteries have three layers of structure, tunica intima, tunica media, and tunica adventitia. Intima tunica is the deepest layer of coronary arteries in which there are antithrombotic molecules such as heparin sulfate, thrombomodulin, and plasminogen activator. In addition, tunica intima also contains substances that regulate the contraction of tunica smooth muscle cell media, called nitric oxide (vasodilators) and prostacyclin (vasoconstrictors). Tunica intima and tunica media seem to be directly related to the atherosclerosis process. Meanwhile, the role of tunika adventisia is unknown. The accumulation of atherosclerotic lesions and hemodynamic stress factors and the degradation of extracellular matrix will cause susceptibility of atherosclerotic plaque fibrous capsules to rupture and form thrombus. Thrombus that occurs in the coronary condition causes acute coronary syndrome, characterized by typical symptoms such as chest pain depending on the thrombus formed. In studying acute coronary syndromes, of course it cannot be separated from understanding the physiology of coronary arteries and the process of atherosclerosis. Therefore, this article aims to briefly explain coronary physiology.

Encapsulation of Plant Biocontrol Bacteria with Alginate as a Main Polymer Material.

One of the most favored trends in modern agriculture is biological control. However, many reports show that survival of biocontrol bacteria is poor in host plants. Providing biocontrol agents with protection by encapsulation within external coatings has therefore become a popular idea. Various techniques, including extrusion, spray drying, and emulsion, have been introduced for encapsulation of biocontrol bacteria. One commonly used biopolymer for this type of microencapsulation is alginate, a biopolymer extracted from seaweed. Recent progress has resulted in the production of alginate-based microcapsules that meet key bacterial encapsulation requirements, including biocompatibility, biodegradability, and support of long-term survival and function. However, more studies are needed regarding the effect of encapsulation on protective bacteria and their targeted release in organic crop production systems. Most importantly, the efficacy of alginate use for the encapsulation of biocontrol bacteria in pest and disease management requires further verification. Achieving a new formulation based on biodegradable polymers can have significant effects on increasing the quantity and quality of agricultural products.